The IRS does not permit you to put a 2015 1099-MISC on your 2016 return.
Instead, if you received a 2015 1099-MISC that you did not file as part of your 2015 return, then you have to amend your 2015 return.
Please see this video from TurboTax explaining the
amendment process if you want to do it yourself -
https://turbotax.intuit.com/tax-tools/tax-tips/IRS-Tax-Return/Video--How-to-Amend-Taxes-That-Are-Alr...
If you want to do the amendment through TurboTax, please read the article at this link - https://turbotax.intuit.com/tax-tools/tax-tips/IRS-Tax-Return/Amending-Your-Income-Tax-Return/INF120...
Normally, you would reopen the return and indicate that you want to amend the return, and then proceed through the interview.